Interventional cardiologists incorporate a variety of diagnostic tools during catheterization procedures in order to plan, guide, and assess therapies. Fluoroscopy is generally used to perform angiographic imaging of blood vessels. In turn, such blood vessel imaging is used by physicians to diagnose, locate and treat blood vessel disease during interventions such as bypass surgery or stent placement. Intravascular imaging technologies such as optical coherence tomography (OCT) and acoustic technologies such as intravascular ultrasound (IVUS) and others are also valuable tools that can be used in lieu of or in combination with fluoroscopy to obtain high-resolution data regarding the condition of the blood vessels for a given subject.
Fractional flow reserve (FFR) can also be used to evaluate a blood vessel during imaging and angiography. Intravascular OCT, IVUS, and FFR are invasive catheter-based systems that collect optical, ultrasound, and pressure data, respectively, from inside blood vessels or with respect to a sample of interest. Angiography is a noninvasive x-ray imaging method that collects data from outside the body during injection of a radio-opaque contrast fluid.
Intravascular optical coherence tomography is a catheter-based imaging modality that uses light to peer into coronary artery walls and generate images thereof for study. Utilizing coherent light, interferometry, and micro-optics, OCT can provide video-rate in-vivo tomography within a diseased vessel with micrometer level resolution. Viewing subsurface structures with high resolution using fiber-optic probes makes OCT especially useful for minimally invasive imaging of internal tissues and organs. This level of detail made possible with OCT allows a clinician to diagnose as well as monitor the progression of coronary artery disease.
Given the complexity of the various technologies described above and the associated complexity of the datasets each of them generate, performing co-registration between two image-based technologies such as OCT and angiography is time consuming. As a result, challenges regarding real time co-registration of intravascular image data and angiography image data remain. Some co-registration techniques depend heavily on user interaction. Unfortunately, taxing an operator with significant user interaction during co-registrations such as requiring manually matching corresponding points in images, a long waiting period for the algorithms to return a co-registration, and finally verifying the results, makes such approaches impractical in many clinical scenarios. In addition, other approaches use data from asynchronous or third party controlled sources which results in timing irregularities. In addition, since contrast agents, such as dyes, are used with some intravascular imaging modalities that interfere with other noninvasive imaging modalities, imaging artifacts and errors can result which interfere with co-registration between such modalities.
Accordingly, a need therefore exists to address one or more of the challenges identified above relating to intravascular imaging and angiography imaging. Embodiments of the invention address these challenges and others.